What is the evidence to show that climate change is happening? 


Evidence for climate change can be seen in ice cores, extreme weather events and changes in nature, such as changes in the migration pattern of birds. Ice cores are extracted from Antarctica and Greenland. Each core shows lots of layers of ice, which vary in size depending on annual snowfall rates. These layers are known as accumulation layers. Ice cores also contain gas bubbles, which tell us about the atmospheric greenhouse concentrations from hundreds of thousands of years ago. These gas bubbles reveal that carbon dioxide concentrations have been increasing since the 19th century. One of the oldest ice core records is the Vostok ice core in Antartica, which can tell us what the climate was like 420,000 years ago! Extreme weather events, such as storms, are becoming more frequent and persistent, highlighting that the climate is changing. An example of an extreme weather event is Hurricane Harvey, which caused major flooding in Texas in 2017. Finally, migration patterns of birds are changing. For example, birds are arriving at the country they choose to breed in one day earlier as global temperature increases by one degree.